> Your code isn’t testing a bite. It’s testing eight bits, so the order of the > instructions can definitely alter the outcome..
Kind regards, Keven Hall > On Feb 16, 2026, at 14:12, David Clark <[email protected]> wrote: > > >> >>> You need to order the TM tests with the most-bits-on flag value first... > > Well, code shouldn't fail just because tests on the same byte of storage > change order. > >>> As Mark suggested, maybe you really want CLI instead of TM in this case? > > I guess Dr. John Ehrman's idea doesn't work in complex bit-testing > scenarios (given that you shouldn't have to "order" the tests from most '1' > bits to least '1' bits). > > Thanks, > Dave Clark > > >> On Mon, Feb 16, 2026 at 3:03 PM Farley, Peter < >> [email protected]> wrote: >> >> You need to order the TM tests with the most-bits-on flag value first >> followed by the next-highest-count-of-bits-on value, etc. >> >> As Mark suggested, maybe you really want CLI instead of TM in this case? >> >> Peter >> >> From: IBM Mainframe Assembler List <[email protected]> On >> Behalf Of David Clark >> Sent: Monday, February 16, 2026 2:46 PM >> To: [email protected] >> Subject: Apparent Test Under Mask Failure >> >> >> Can someone please explain to me how the following fails to drop through to >> >> the actual test for C5? The request at d'8000' is 'E' (x'C5', b'11000101') >> >> but the code is taking the 'D' (x'C4', b'11000100') branch. Why? >> >> >> >> The condition code should result in mixed -- not ones. Am I going to have >> >> to change from bit mask testing to 'CLI' testing? >> >> >> >> 000872 91C4 8000 00000 1842+ TM >> >> REQU_DELETE,L'REQU_DELETE >> >> 000876 A714 0124 00ABE 1843+ JO TXTDLET >> >> ...snip... >> >> 0008C2 91C5 8000 00000 1994+ TM >> >> REQU_2EBCDIC,L'REQU_2EBCDIC >> >> 0008C6 A714 02D7 00E74 1995+ JO TXT2EBC >> >> >> >> The bit mask flags are defined as follows--using my own macros based on the >> >> late Dr. John Ehrman's SHARE presentation on the subject. >> >> >> >> 000000 300=TXTREQU DS CL1 >> >> 00000 000C4 308+REQU_DELETE EQU *-1,C'D' >> >> 00000 000C5 310+REQU_2EBCDIC EQU *-1,C'E' >> >> ...snip... >> >> >> >> Sincerely, >> >> Dave Clark >> >> -- >> >> This message and any attachments are intended only for the use of the >> addressee and may contain information that is privileged and confidential. >> If the reader of the message is not the intended recipient or an authorized >> representative of the intended recipient, you are hereby notified that any >> dissemination of this communication is strictly prohibited. If you have >> received this communication in error, please notify us immediately by >> e-mail and delete the message and any attachments from your system. >>
